In recent years, with the advancements in speed-up and energy conservation of the machines, toners having excellent low-temperature fixing ability and hot offset resistance are in demand.
Patent Publication 1 discloses, as an objective of providing a toner which is excellent in all of low-temperature fixing ability, offset resistance, pulverizability, dispersibility of an internal additive, and storage property, a toner containing, as resin binders, a polyester resin (A) and a polyester resin (B) having a softening point calculated from the softening point of the polyester resin (A) plus 10° C. or more, wherein the above polyester resin (A) is a resin having a polyester unit obtained by polycondensing an alcohol component containing 1,2-propanediol in an amount of 65% by mol of the dihydric alcohol component, and a carboxylic acid component containing a (meth)acrylic acid-modified rosin, and wherein the above polyester resin (B) is a resin having a polyester unit obtained by polycondensing an alcohol component containing 1,2-propanediol and 1,3-propanediol in a total amount of 70% by mol or more of the dihydric alcohol component and a carboxylic acid component containing a purified resin.
Patent Publication 2 discloses, as an objective of providing a toner having degradability which has excellent fixing ability, fixing strength, offset resistance, and blocking resistance, a toner for electrostatic image development, characterized in that the toner contains a polyester resin obtained by subjecting a composition containing lactic acid and a hydroxycarboxylic acid having three or more functional groups to a dehydration polycondensation, and a colorant.